Sheet strippers for rotary duplicators



Aug. 14, 1956 Rn-zERFELD ETAL 2,758,539

SHEET STRIPPERS FOR ROTARY DUPLICATORS Filed Jfily 22, 1952 2Sheets-Sheet 1 Fly. 1

Inventors:

LHEI-rq RITZERFELD 5 R ARD fiITzERFEl-D Aug. 14, 1956 w. RITZERFELDETAI- SHEET STRIPPERS FOR ROTARY DUPLICATORS 2 Sheets-Sheet 2 Filed July22, 1952 ,FTN

Inventors.- RITZER FELD WILHE'LM @ERHARD RITZER FELD BY. W

United States Patent Otfice 2,758,539 Patented Aug. 14, 1956 2,758,539SHEET STRIPPERS FOR ROTARY DUPLICATORS Wilhelm Ritzerfeld,Berlin-Dahlem, and Gerhard Ritzerfeld, Berlin-Grunewald, GermanyApplication July 22, 1952, Serial No. 300,208 Claims priority,application Germany August 8, 1951 11 Claims. (Cl. 101-91) The presentinvention relates to rotary duplicators.

It is an object of the invention to provide an improved rotaryduplicator of the type allowing to reproduce texts separated from eachother on a printing form by more than one line in immediatejuxtaposition on a copy sheet.

In connection with such duplicators, it is necessary for the movementsof the copy sheets to be printed to be exactly matched to movements ofdifferent individual elements of the duplicators. Accordingly, it is amore specific object of the invention to provide simple and yet reliablemeans for co-ordinating such movements.

It is a further object of the invention to provide improved means forreliably separating copy sheets from the printing drum while the same isrotated from the end of one text to the beginning of another textseparated from the first text on the printing form by more than oneline.

These and other objects and advantages of the invention will becomeapparent to those skilled in the art from the following detaileddescription of an embodiment of the invention when read in conjunctionwith the accompanying drawings, in which:

Fig. 1 is a side view of a rotary duplicator of the invention in itsinitial position;

Fig. 2 is a similar side view of the rotary duplicator of Fig. 1 in itsposition in which the printing of a first text on a copy sheet begins;and

Fig. 3 illustrates a section along the line 3-3 of Fig. 2, which forclarity has been expanded.

The printing drum 1 shown in the drawings is rotatable in the directionof the inscribed arrow together with a printing form 3 attached to theprinting drum 1 by a clamping device 2. The term copy sheet as usedherein is intended to embrace paper sheets, cards, labels, and the likeon which a text is to be reproduced by the duplicator. On the movementof the printing drum 1, the rotation of a cam disc 4 for controlling theprint of a first text (hereinafter called heading) and the rotation of acam disc 5 for controlling the print of a subsequent text (hereinaftercalled the lines) are dependent, the cam discs 4 and 5 being linked tothe printing drum 1 by means of gears that are known per se and aretherefore not shown for clarity. The print of the heading on a copysheet 6 is usually effected by means of stamps or the like printingmatrices arranged on the printing drum at the vicinity of the clampingdevice 2, while the print of the lines is usually derived from a mirrorscript original prepared in the usual manner by a typewriter andconstituting the printing form 3.

' Cams of the cam discs 4 and 5, co-operate with a toggle leverarrangement 9, 10, 11, 12, 13, which moves a counter-pressure roller 8mounted in supporting levers 7 towards and away from the printing drum 1for cooperation therewith in timed relationship to the rotation of theprinting drum 1. After the leading end of the copy sheet 6 has passedthe line 14 where the printing takes place, the leading end of the copysheet 6 is separated from the printing form 3 by strippers 16 keyed to,

and rotatable with, a shaft 15. The rotational move-' ment of thestrippers 16 is controlled and effected by a 2 control lever 17 arrangedon the same shaft 15. The control lever 17 is operated by a control disc19 (Figs. 2 and 3) arranged on a shaft 18 of the printing drum so as torotate bodily with the printing drum.

While the copy sheet 6 is inserted into the rotary duplicator, thestrippers 16 engage slots 20, grooves, or the like provided in theperiphery of the printing drum 1 and the clamping device 2, as can beseen from Fig. 2.

After the leading end of the copy sheet 6 has passed the line ofprinting 14, the strippers 16 are rotated by the control disc 19 and thecontrol lever 17 to assume the position indicated in dash-dotted linesin 'Fig. 2 and, thus, separate the leading end of the copy sheet 6 fromthe printing form 3. After the strippers 16 have been rotated out of theslots 20 or the like by means of the control disc 19 and the controllever 17, the further control of the movement of the strippers 16 iselfected in dependence on the movements of the cam discs 4 and 5. Tothis end, a control movement initiated by the cam discs 4 and 5 istransferred to a follower 9 of the toggle lever arrangement 9, 10, 11,12, 13. To the follower 9, a lug 21 is linked which acts on a rotatablelever 22 mounted rotatably on'the shaft 15. During the movement of therotatable lever 22, an abutment stud 23 arranged thereon bears against alever 24 keyed to the shaft 15. As can be seen from Fig. l, the lever 24then rotates the strippers 16 from the position indicated in dash-dottedlines in which, as likewise indicated in dash-dotted lines, thecounter-pressure roller 8 is removed from the printing drum 1, that isto say between the printing of the heading and the printing of thelines, into the position indicated in full lines in which the strippers16 are out of range of the counter-pressure roller 8 which, now, againpresses against the printing drum 1 as indicated in full lines.

A spring 25 arranged between the rotatable lever 22 and the lever 24fixed to the shaft 15 causes the lever 24 to be permanently urgedtowards the stud 23 of the rotatable lever 22. During the control of thestrippers 16 by the control disc 19 and the control lever 17, the lever24 is removed from the stud 23, while after the termination of 'thiscontrol process the lever 24 is caused by the spring 25 to bear againstthe stud 23.

In order to hold the copy sheet 6 in its position relative to the lineof printing 14 while the counter-pressure roller.

8 is removed from the printing drum 3, clamp springs 27 fixed on a shaft26 are pressed against the copy sheet 6. This is effected by means of afurther control disc 28 (Fig. 1) likewise arranged on the shaft 18 ofthe printing drum 1 and rotatable therewith. The movement of the furthercontrol disc 28 is transferred to the clamp springs 27 by means'of acontrol lever 29 connected to the shaft 26 (see also Fig. 2).

From the foregoing description, it will be seen that a rotary duplicatorhas been provided, wherein all the successive operations required forprinting a copy sheet from a printing form are controlled in a simpleand reliable manner by the movements of the printing drum 1 and the.counter-pressure roller 8 co-operating therewith, the coun-,

ter-pressure roller 8 being moved in timed relationship towards and awayfrom the printing drum 1 carrying the printing form 3 and being mountedin supporting levers 7 and controlled by the toggle lever arrangement'9, 1d, 11, 12, 13, which supporting levers 7 are rotatably mounted. Therotatably arranged strippers 16 engage,

while the latter is beingrotated forwards in order to' bring a next lineof' the printing form'into'the printing position so as to be printed onthe copy sheet 6 H when the same is again pressed against the printingdrum 1 by the ;counter-pressureffroller 8 controlled by the cam discs 4and 5 and the toggle lever arrangement 9, 10, 11, 12, 13. In thisrespect, the provision is of importance of the control disc 19 connectedto, and rotatable with, the printing drum 1, which control disc servesto rotate the strippers 16 by means of the control lever 17 and thelever 24 which is rotatably arranged on the shaft and is urged by theaction of the spring 25 against the abutment stud 23. I

After the strippers: 16 have become active, that is to say after thecopy sheet 6 has been removed from the printing form 3 by the strippers16, then the control of the said strippers is subsequently effected independence on the movements of the counter-pressure roller 8 away from,and towards, the printing drum 1 in such a manner that the rotatablelever 24 supportingthe strippers 16 and arranged on the shaft 15 islinked by means of the connecting lug 21 to the follower 9 sensing thecam discs 4 and 5 for controlling the movements of the counterpressureroller 8 towards and away from the printing drum 1.

Moreover, during the time in which the copy sheet 6 has to be keptseparated from the printing form 3 in order to bring the respective lineto be printed of the printing form into the printing position, it isnecessary for the copy sheet 6 to be kept at rest. This is effected inthat the copy sheet 6 is held in its position by clamp springs 27 whilethe counter-pressure roller 8 is removed from the printing drum 1, theclamp springs 27 being controlled by a further control disc 28 rotatingtogether with the printing drum 1.

It should be clearly understood that the embodiment described andillustrated is given by way of example only. Many modifications,omissions and additions are possible without departing from the spiritof this invention; For example, the clamp springs 27 for holding thecopy sheet 6 may be replaced by any other suitable holding device.Again, the toggle lever arrangement 9, 10, 11, 12, 13 may be replaced byany other suitable linkage.

We claim:

1. A rotary duplicator, comprising, in combination, a rotary printingdrum adapted to support a printing form; a counter pressure rollercooperating with said printing drum and adapted to press a copy sheetagainst the printing form; movable supporting means supporting saidcounter-pressure roller for movement toward and away from said printingdrum; rotary cam means driven from said printing drum and connected tosaid movable supporting means for moving said counter-pressure rollertoward and away from said printing drum during each revolution of thesame for printing spaced portions of the printing form in adjacentposition on the copy sheet; a movable support; strippers mounted on saidmovable support adjacent a bight between said drum and said counterpressure roller and being movable toward and away from said printingdrum and adapted to separate a copy sheet from the printing drum; firstoperating means driven from said printing drum in timed relationshipwith said 'cam means for moving said strippers in timed relationshipwith said printing drum so as to move the leading edge of a copy sheetaway from said printing drum; rotary cam means and to said strippers formoving said strippers in timed relationship with said counter pressureroller so that said strippers move away from said drum and are adaptedto separate acopy sheet from said printing drum whenever said counterpressure roller moves away from said printing drum while said printingdrum continues rotation for moving, an undesired portion of the printingform past the copy sheet.

2. A rotary duplicator, comprising, in combination, a rotary printingdrum adapted to support aprinting form; a counter pressure roller.cooperating with said printing and second operating means connected tosaid drum and adapted to press a copy sheet against the printing form;movable supporting means supporting said counter pressure roller formovement toward and away from said printing drum; rotary cam meansdriven from said printing drum and connected to said movable supportingmeans for moving said counter pressure roller toward arid away from saidprinting drum during each revolution of the same for printing spacedportions of the printing form in adjacent position on the copy sheet; aturnable supporting shaft; strippers secured to said shaft projectinginto a bight between said printing drum and said counter pressureroller; a cam track secured to said printing drum for rotationtherewith; a first control lever secured to said supporting shaft andhaving a free end guided in said cam track so that in predeterminedpositions of said printing drum said strippers are rocked away from saidprinting drum in timed relationship with said cam means for separatingthe leading edge of a copy sheet from the printing drum, and so that inother predetermined positions of said printing drum said cam trackreleases said free end of said first control lever; a second operatinglever secured to said supporting shaft; an operating member freelyturnably mounted on said supporting shaft and having an abutment; aspring connecting said second operating lever with said operating memberand urging said second operating lever into engagement with saidabutment; motion transmitting means connecting said operating memberwith said cam means and with said movable supporting means of saidcounter pressure roller in such manner that when said counterpressureroller moves away from said printing drum, said operating member isturned on said supporting shaft so that said spring moves said secondcontrol lever to a position corresponding to a movement of saidstrippers away from said printing drum for separating the copy sheetfrom said printing drum whenever said counter pressure roller moves awayfrom said printing drum while said printing drum continues rotation formoving an undesired portion of the printing form past the copy sheet.

3. A rotary duplicator comprising, in combination, a rotary printingdrum adapted to support a printing form; a counter pressure rollercooperating with said printing drum and adapted to press a copy sheetagainst the printing form; movable supporting means supporting saidcounter pressure roller for movement toward and away from said printingdrum; rotary control means driven from said printing drum and connectedto said movable supporting means for moving said counter pressure rollerduring each revolution of said printing drum toward and away from saidprinting drum for printing spaced portions of the printing form inadjacent position on the copy sheet; a movable support; stripper meansmounted on said movable support adjacent a bight between said printingdrum and said counter pressure roller and being movable toward and awayfrom said printing drum between initial position adapted to engage theleading edge of a copy sheet and a plurality of positions farther spacedfrom said printing drum for separating the copy sheet from the printingform during rotation of said printing drum; first operating means drivenfrom said printing drum for moving said stripper means in timedrelationship with said printing drum out of said initial position so asto move the leading edge of a copy sheet away from said printing drum;and second operating means connecting said rotary control means to saidstripper means for moving said stripper means in timed relationship withsaid counter pressure roller so that said stripper means move betweensaid farther spaced positions toward and away from said printing drumfor separating a copy sheet from said printing drum whenever saidcounter pressure roller moves away from said printing drum while saidprinting drum continues rotation for moving an undesired portion of theprinting form past the copy sheet,

4. A rotary duplicator comprising, in combination, a

rotary printing drum adapted to support a printing form, said rotaryprinting drum being formed with circumferential grooves; a counterpressure roller cooperating with said printing drum and adapted to pressa copy sheet against the printing form; movable supporting meanssupporting said counter pressure roller for movement toward and awayfrom said printing drum; rotary control means driven from said printingdrum and connected to said movable supporting means for moving saidcounter pressure roller during each revolution of said printing drumtoward and away from said printing drum for printing spaced portions ofthe printing form in adjacent position on the copy sheet; a movablesupport; stripper means mounted on said movable support adjacent a bightbetween said printing drum and said counter pressure roller and beingmovable toward and away from said printing drum between initial positionprojecting into said grooves in said printing drum and adapted to engagethe leading edge of a copy sheet and a plurality of positions fartherspaced from said printing drum for separating the copy sheet from theprinting form during rotation of said printing drum; first operatingmeans driven from said printing drum for moving said stripper means intimed relationship with said printing drum out of said initial positionso as to move the leading edge of a copy sheet away from said printingdrum; and second operating means connecting said rotary control means tosaid stripper means for moving said stripper means in timed relationshipwith said counter pressure roller so that said stripper means movebetween said farther spaced positions toward and away from said printingdrum for separating a copy sheet from said printing drum whenever saidcounter pressure roller moves away from said printing drum while saidprinting drum continues rotation for moving an undesired portion of theprinting form past the copy sheet.

5. A rotary duplicator as claimed in claim 4 wherein said movablesupporting means include a plurality of articulated levers, one of saidarticulated levers supporting said counter pressure roller.

6. A rotary duplicator as claimed in claim 5 wherein said rotary controlmeans include a plurality of coaxial cam disks, and wherein one of saidarticulated levers is a cam follower engaging said cam disks.

7. A rotary duplicator as claimed in claim 4 wherein said movablesupport is a freely turnable shaft; and wherein said stripper means aresecured to said shaft.

8. A rotary duplicator as claimed in claim 4 and including a cam memberconnected to said printing drum for rotation therewith; a holding meansfor holding a copy sheet stationary and being located adjacent anotherbight between said printing drum and said counter pressure roller, saidholding means being movable between an operative holding position and aninoperative releasing position; and motion transmitting means connectedto said holding means and including a cam follower member engaging saidcam member so that said holding means is moved to said operative holdingposition whenever said counter pressure roller is in a position spacedfrom said printing drum.

9. A rotary duplicator comprising, in combination, a rotary printingdrum adapted to support a printing form; a counter pressure rollercooperating with said printing drum and adapted to press a copy sheetagainst the printing form; movable supporting means supporting saidcounter pressure roller for movement toward and away from said printingdrum; first control cam means driven from said printing drum; aplurality of articulated levers connected to said movable supportingmeans and including a cam follower lever engaging said first control cammeans for moving said counter pressure roller during each revolution ofsaid printing drum toward and away from said printing drum for printingspaced portions of the printing form in adjacent position on the copysheet; a turnable shaft; stripper means secured to said shaft andprojecting and away from said printing drum between an initial positionadapted to engage the leading edge of a copy sheet and a plurality ofpositions farther spaced from said printing drum; second cam meansdriven by said printing drum; a cam follower lever secured to saidturnable shaft and having a free end engaging said second cam means formoving said stripper means in timed relationship with said printing drumout of said initial position so as to move the leading edge of a copysheet away from said printing drum; another lever secured to saidturnable shaft; an operating member freely turnably mounted on saidturnable shaft; an abutment of said operating member engaging said otherlever during turning movement of said operating member; spring meansconnecting said operating member with said other lever for urging thesame against said abutment; and a link' connecting said operating memberwith one of said articulated levers whereby said stripper means aremoved in timed relationship with said counter pressure roller betweensaid farther spaced positions.

10. A rotary duplicator comprising, in combination, a driven printingdrum adapted to support a printing form and to move the same through aprinting line; a counter pressure roller cooperating with said printingdrum at said printing line; movable supporting means supporting saidcounter pressure roller for movement between an operative positionengaging printing drum and an inoperative position spaced from saidprinting drum; supply means for supplying sheets to said printing drumso that said counter pressure roller and said printing drum grip asupply copy sheet along said printing line and transport the same inprinting engagement with said printing form only when said counterpressure roller is in said operative position; holding means formaintaining the copy sheet stationary when said counter pressure rolleris in said inoperative position; rotary cam means driven from theprinting drum so as to turn in timed relationship with said printingform, said cam means engaging said movable supporting means and movingthe same and therewith said counter pressure roller automatically andpositively during each revolution of said printing drum through aselected cycle of movements from said operative position to saidinoperative position when undesired portions of said printing form aremoved by said printing drum past said printing line, and again to saidoperative position for printing desired portions of the printing form onthe copy sheet adjacent to matter previously printed by said printingform; a turnable shaft; stripper means secured to said shaft andprojecting into a bight between said printing drum and said counterpressure roller; and linkage means connecting said movable supportingmeans with said turnable shaft for turning said shaft in timedrelationship with the movement of said counter pressure roller so thatsaid stripper means separate the copy sheet from said printing drumwhenever said counter pressure roller moves away from said printing drumwhile said printing drum continues rotation thereof.

11. A rotary duplicator as claimed in claim 10 wherein said movablesupporting means include a plurality of articulated levers, one of saidlevers being a cam follower lever engaging said cam means, and whereinsaid linkage $62118 connect said cam follower lever with said turnable at. 7

References Cited in the file of this patent UNITED STATES PATENTS653,762 France Mar. 27, I929

